1. Field of the Invention
The present invention relates to a two-stage rubber switch suitable for use in automotive vehicle, for instance.
2. Description of the Prior Art
A number of various switches are generally used in various industrial fields without being limited to automotive vehicles; however, rubber switches are widely used in the automotive vehicle field, in particular from the standpoints of reliability, space, operability, etc.
FIG. 1(a) shows a power window switch for an automotive vehicle, by way of example of these rubber switches. This switch used to manually open or close a window glass is composed of a housing 101, a pair of push bodies 102 and 103, a contact wiring board 104, a rubber switch member 105, and a pivotal operation knob 106 on the push bodies. In operation, when the operation knob 106 is pivoted counterclockwise, for instance, the rubber buckling portion 108 of the rubber switch member 105 is pushed or buckled by the push body 102 to close a contact portion arranged on the contact wiring board 104, so that a window glass moves upward. In contrast, when the operation knob 106 is pivoted clockwise, since the rubber buckling portion 109 is buckled to close another contact portion, the window glass moves downward.
In the prior-art rubber switch as described, however, since the two contact portions are opened or closed at a single stage operation on each side, the window glass can be opened or closed only manually. Therefore, where automatic window glass opening/closing operation is further required, another similar switch must be provided in parallel to the manual switch as shown in FIG. 1(a). In other words, although this rubber switch is small in the number of parts, high in reliability and low in cost, there exists a problem in that a large space is required when two similar rubber switches are arranged side by side.
To overcome the above-mentioned problem, a two-stage operation power window switch is disclosed in Japanese Published Unexamined (Kokai) Utility Model Appli. No. 54-15278, as shown in FIG. 1(b). This two-stage operation switch is composed of a pivotal operation knob 121, a pair of first contact switches 122 and 123, and a pair of second contact switches 124 and 125. When the operation knob 121 is pivoted counterclockwise, for instance, the contact switch 122 is first closed and then the contact switch 124 is closed in sequence at two stage operation on each side, respectively.
In this prior-art two-stage operation switch, however, since the number of parts is large and further each switch is formed of a thin metallic plate, there exists a problem in that the assembly is not easy because fine adjusting work is inevitably required, so that the manufacturing cost is high and the reliability is low.
As described above, in the first prior-art rubber switch, although the reliability is high and the cost is low, there exists a problem in that the mounting space is not economized. Further, in the second prior-art two-stage switch, although the mounting space is small, there exist problems in that the reliability is low and the assembly cost is high.